1. The Field of the Invention
The present invention is directed to rendering enhanced and interactive file-based data and, more particularly, to rendering enhanced file-based state information in a time-shifted manner.
2. Related Technology
The computer and television industries are making large strides in developing technology that will enable a single device to provide the dual functionality of the computer and the television. For instance, the computer is becoming more adept at rendering audio and video data in a manner that simulates the broadcast infrastructure of the television industry. Likewise, the television and computer industries are developing new standards that enable web-based content to be broadcast to the television.
Two emerging standards for broadcasting enhanced, interactive, web-based content include the Advanced TeleVision Forum (ATVEF) standard and the Broadcast HTML standard. Currently, the computer and television industries are working on developing suitable receivers and broadcasting devices for enabling the broadcast of web-based content to the television set.
One problem with broadcasting enhanced and interactive file-based content, however, is that file-based state information may become invalidated when the broadcast of the program is rendered in a time-shifted manner. A program is rendered in a time-shifted manner, for instance, when the program is played at either a different time or in a different sequence than it was recorded.
One device that has been configured to enable this time-shifting functionality is the Programmable Video Recorder (PVR). The PVR may, for instance, record broadcast data into a temporary buffer and then later play the recorded data from the temporary buffer. One advantage of the PVR, over other devices like the VCR, is the ability of the PVR to record data at the same time other data is read and rendered from the temporary buffer. Accordingly, a viewer may use the PVR to watch previously recorded programming at the same time new programming is being recorded.
The PVR also enables a viewer who is watching a live broadcast to temporarily pause the display of the broadcast and then to later resume watching the broadcast at the point it was paused. This is possible because the PVR continuously records the broadcast to the buffer even while the program is being paused. While the program is temporarily paused, the viewer may choose to watch a replay of a desired segment. In a recorded program, the viewer may also choose to skip forward over undesirable segments, such as commercials, for instance.
However, the functionality of enabling the viewer to skip over portions of the recorded broadcast may result in the invalidation or failure to recognize certain enhanced file-based state data that may be embedded within the broadcast. For instance, in one embodiment, the broadcast may include a baseball game that is transmitted with enhanced file-based state data, such as ATVEF data, for maintaining a live scoreboard of the game. After each score or inning new file-based state data may be transmitted to update the scoreboard so that the state of the game may be correctly reflected. However, if the entire game has been recorded and the viewer only begins watching the game in the middle of the fourth inning, for example, then the scoreboard may incorrectly reflect the most recently received scoreboard state information (e.g., the final score information), rather than the fourth inning scoreboard state information.
In another embodiment, enhanced file-based state data is received during the broadcast of commercials. This may be done, for instance, to provide ample time for processing the enhanced data so that it can be displayed as soon as the commercials end. In the present embodiment, the enhanced data may include ATVEF data that provides end of inning statistics on the teams and players. However, if the viewer decides to skip over the commercials, then the statistical data may not be read and properly updated by the PVR, thereby preventing the data from being rendered at the appropriate time with respect to the program.
Yet another problem experienced when recording enhanced file-based state data is that ATVEF standards result in some of the same data being transmitted redundantly. In particular, ATVEF data files are typically placed into one or more packages that are each uniquely identified by a GUID (Global Unique Identifier). Prior to being transmitted, each of these packages is broken up into “N” packets and “M” packets that are labeled by the GUID, the total number of packets in the GUID, and a their unique sequence in the GUID. This enables the ATVEF data files to be reconstructed upon being received. The M packets are typically transmitted redundantly in case some of the packets are not received.
Sometimes more than a single copy of an M packet is received. The redundant M packets may be stored within the temporary buffer with the other broadcast data. However, storing duplicative M packets represents a waste of resources and storage space, particularly when considering the finite storage capacity of the PVR buffer.